The Rail Doctor’s Guide: EN 17397 Rail Defects

Introduction to EN 17397-1

Steel rails are incredibly tough, but they are not invincible. Under the relentless pounding of wheels, they develop microscopic cracks, internal fatigue, and surface wounds. For decades, the “bible” for identifying these problems was the famous UIC Leaflet 712 (Code of Rail Defects). Today, this knowledge has been formalized into the European Standard EN 17397-1, titled “Railway applications – Rail defects – Part 1: Rail defect management.”

This standard provides a common language for every railway engineer in Europe. Instead of saying “that weird bumpy crack,” an engineer says “Defect 227 (Squat).” This precise coding allows infrastructure managers to track the health of their network, predict failures, and schedule grinding trains before a rail breaks.

Snippet Definition: What is EN 17397?

EN 17397-1 is a European standard that specifies the system for managing rail defects. It replaces and expands upon the classification catalog of UIC Leaflet 712. It defines the numeric coding system for defects (based on location and origin), the methods for detection (referencing EN 16729), and the decision criteria for whether a rail needs immediate replacement or long-term monitoring.

The Coding System (The “Diagnosis”)

EN 17397 (like its predecessor UIC 712 / IRS 70712) uses a logical numbering system to categorize defects. This helps in statistical analysis.

• First Digit (Location):
  • 1xx: Defect at Rail Ends (Joints/Welds).
  • 2xx: Defect in the Plain Line (Away from joints).
• Second Digit (Position in Profile):
  • x1x: Head (Internal).
  • x2x: Head (Surface).
  • x3x: Web.
  • x5x: Foot.

Common Defect Examples

Defect Management Process

EN 17397-1 emphasizes that naming the defect is only step one. The standard outlines a full lifecycle approach:

1. Detection: Using Ultrasonic Testing trains (to find internal 211s) or Eddy Current/Video inspection (to find surface 2223s).
2. Classification: Assigning the code and measuring severity (e.g., crack depth, length).
3. Action:
   • Keep under observation: If the crack is small.
   • Maintenance: Rail Grinding (to remove Head Checking) or Weld Repair.
   • Removal: Cutting out the rail section if the defect poses a fracture risk (e.g., a deep Squat).

Comparison: EN 17397 vs. UIC 712

Why switch to the EN standard?